Jonathan Beale
Defence correspondent

The US operates from more than a dozen military bases in the UK.

The US Air Force's main bases in the UK are: RAF Lakenheath in Suffolk - home to the 48th Fighter Wing operating F-15 and F-35 jets; RAF Mildenhall in Suffolk - mainly a base for US air refuelling tankers; RAF Fairford in Gloucestershire - a large airbase which periodically hosts US Air Force long range bombers including B-52s, B1 and B2s.

RAF Fairford has recently been used by the US Air Force to carry out strikes on Iran, following a decision by the UK Government in March to allow the Trump administration to conduct so-called “defensive operations” against Iranian military targets.

It’s been reported the threat alert at RAF Fairford has recently been raised to Delta - the highest level, meaning there’s intelligence relating to an imminent potential attack.

The threat level at RAF Lakenheath and Mildenhall is believed to have been raised to Charlie - the second highest level when intelligence suggests there could be a potential attack.

Image source, BBC Radio 4 Today programme

During his interview on the Today programme, Defence Secretary Wes Streeting renews his thanks to the farmer who rang the police, and talks about the status of the investigation currently under way.

"At this stage in the investigation, I'm not in a position to comment on the identities of these individuals, or their aims and motivations," he says.

Further information will be provided to the public as the investigation unfolds, about the individuals and their backgrounds, he adds.

The defence secretary says the police should be given space and time to investigate, and refuses to speculate about Iranian involvement.

"We know that it is a matter of public record, that the Iranian regime is one that would do harm to our interests and to our allies given the chance, and I'm proud of the work that we do, all year and every year, to detect and to deter and prevent Iran from carrying out acts of harm."

Nick Johnson
Reporting from the scene

I’m at the edge of the police cordon leading down to the village of Whelford, where those three vans were spotted and more than 80 homes evacuated.

There is no timetable for the cordon to be lifted, which is frustrating commuters, delivery drivers and school buses.

I was here in March when the American B-1 and B-52 bomber planes first arrived, having hit targets in Iran.

I was struck by how close members of the public could get to the perimeter fence. With the base being so vast and located in a rural area, it felt very accessible at the time.

Now, almost every road which gets within a few hundred metres of the base is blocked by police.

Behind the police cordon, a bomb disposal team was deployed on Sunday to examine a number of vehicles, police said.

Pictures from a news helicopter showed a remote-controlled robot being used to inspect the stationary white vans near Whelford.

Gloucestershire Constabulary's Temporary Chief Constable Maggie Blyth said on Sunday night that the disposal unit was still examining the three vehicles and BBC reporters at the scene have been told the vans remain in place this morning.

Matty Edwards
Live page reporter

Responding to claims that the authorities "dropped the ball" by allowing the suspects to get so close to residents' homes, former British diplomat Lord Peter Ricketts says vigilance from the public is "crucial".

"I think we should wait to see the evidence and whether in fact the intelligence community was aware of this plot - something President Trump said last night suggested they may have been," Ricketts tells the BBC.

"But whether or not they were, vigilance from members of the public is crucial because the police and security services can't be everywhere all the time," he adds.

"We have to think in terms of a whole-society approach to this new world where a number of states regard us as the enemy."

A clear inconsistencypublished at 08:16 BST

08:16 BST

Frank Gardner
Security correspondent

Image source, Reuters

There is a clear inconsistency here between the detailed and convincing account given by the local farmer who sounded the alarm when she saw the masked and hooded men near the vans and the claim by Donald Trump that "we have had these men under view for a long time".

If the US president’s words are correct then somebody was asleep at the wheel in allowing these men to get so close to the base as to trigger what’s being called a major incident.

But Whitehall officials have been clear that this was not an "intelligence-led operation".

In those instances Counter Terrorism Policing (CTP) work closely with investigations officers from MI5 to track suspects and aim to arrest them in what is often a frighteningly short window between gathering enough incriminating evidence to convict them in court but not waiting so long that the public is put in danger.

Nothing about this case looks like that.

Wes Streeting is speaking next to the Today programme on BBC Radio 4.

You can listen to his interview live at 0810 BST by listening here.

Streeting concludes his appearance on BBC Breakfast by saying we have to maintain our advances, maintain our capabilities, and protect our country.

"We have to defend our country, and that is a price we have to pay for the freedom and liberty that we enjoy, and I will continue to make that case as defence secretary," he says.

"Increasing investment in defence does come with choices and trade-offs, and I would argue very strongly that in the dangerous and turbulent world we find ourselves in, investment in defence is a price worth paying.

"As we invest in defence, we will do so in a way that builds industry, jobs and opportunities in this country."

Streeting's attention is drawn to Donald Trump being asked if there was any link between the arrested men and Iran, and the US president saying information will be shared "very soon".

"How soon?" Streeting is asked.

He says it will depend on the police operation, and that this is not the time for him to speculate.

"As soon as we can keep the public informed, we will. I would just ask people for a bit of forbearance to give the police and security services the time and space to do their job," he adds.

"We'll report back with further information as soon as we can."

Streeting is asked about the local farmer who says she called the Ministry of Defence's police after spotting the five men, but didn't get a response.

The defence secretary reiterates that he can't comment as a police investigation is under way.

Streeting is asked if, given that the investigation is live, Donald Trump should have commented on the incident.

Streeting doesn't answer this question directly, instead saying he is "really proud" of the UK's defence partnership with the US.

He adds he is also "proud of the fact" the UK's professionalism was recognised by President Trump.

Streeting says he is fairly limited in what he can say.

He says the local farmer who rang the police after spotting a group of "hooded and masked men" near RAF Fairford had a "partial picture" of what's been happening.

"I won't go beyond that, in terms of commenting on operational security matters," he adds.

The more we show about our operations and how they're conducted, is valuable insight to those who would do us harm, he tells BBC Breakfast.

He says he understands it's frustrating for the public that he can't share more - but it is "a small price to pay" to protect the integrity of the police and security services.

Image source, Getty Images

Defence Secretary Wes Streeting is now talking to the BBC about yesterday's incident.

He reiterates that five men have been arrested and that an investigation is "well under way".

Streeting goes on to issue an "enormous thank you" to local members of the public for showing "vigilance" and "forebearance".

Over 80 houses were evacuated, he says.

Streeting also thanks the police, security services and counter terror police for how the handled the incident.

RAF Fairford is located in the Cotswolds, about four miles (6.4km) south of the town of Fairford, which sits along the River Coln.

The site shares a long history with the American military, and has recently been used by US warplanes as a staging post for strikes on Iran.

With its long runway, the base is suitable for use by the United States' heavy bomber aircraft.

The area is typically quiet but about 170,000 people descend on the RAF site every July for the Royal International Air Tattoo, the largest military show in the world.

The event was cancelled this year due to the war between the US, Israel and Iran.

Defence Secretary Wes Streeting says the investigation into the events near RAF Fairford is now "well under way".

He tells Radio 5 Live Breakfast it was difficult for him to comment further due to the live investigation.

Asked whether the arrests near the RAF base were based solely on a random tip-off from a member of the public or a more sophisticated surveillance operation, Streeting says: "Firstly I want to pay tribute to that member of the public for her vigilance, she’s done exactly what we would hope a member of the public would do in the situation she found herself in.

"She will of course only have had a partial view, and I don’t want to go beyond and stray into kind of operational and security detail at this stage.

"But I think we can be proud of the work that our police, counterterrorism police and security services do to keep us safe."

Streeting adds that "we have very robust tried and tested methods for protecting all of our bases around the UK and around the world".

Edward Rowe
Reporting from the scene

Despite the continuing police presence around the airbase this morning, the overwhelming sense here is of a peaceful rural location.

This might be an international incident generating commentary from both sides of the Atlantic, but nobody told the birds.

Since I arrived here at 06:00 BST this morning, parked next to a couple of farmers fields, it’s felt like a classic English countryside scene. A misty autumnal morning filled with birdsong and the smell of manure.

It couldn’t feel further from the corridors of power on both sides of the Atlantic where it is being discussed. The flashing lights of the police cordon are the only signs of the severity of the situation.

We're expecting Defence Secretary Wes Streeting to appear on BBC Breakfast at around 07:30 BST and to be speaking to Radio 4's Today programme at 08:10 BST.

You can follow BBC Radio 4 and BBC Breakfast TV in our live streams at the top of the page.

We'll be bringing you the key lines here.

Bea Swallow
Live page reporter

The farmer who alerted police to the suspicious activity near RAF Fairford believes "someone dropped the ball" by allowing the suspects and their vehicles to get so close to residential properties.

She told the BBC the three white vans were parked within metres of neighbours' homes - with those sleeping inside unaware of the potential danger.

"We need to be able to trust that the relevant authorities will take appropriate steps to monitor and manage threats to the communities who live and work in close proximity to the base," she said.

"It shouldn’t be necessary for someone like me to alert RAF Fairford of the presence of three large suspicious vehicles and a group of masked men."

The farmer, who chose to remain anonymous, said the incident left her with the impression that authorities were "hyper focused and vigilant" on protecting the base, but "had absolutely no regard for our village".

Edward Rowe
Reporting from the scene

I’ve just arrived at the cordon and it’s all quiet with one police car on the scene, its lights illuminating the gloom, not letting anyone through.

It means the people evacuated yesterday from the 85 homes in the village of Whelford are still waiting to return home.

Police have told me this morning only army personnel and emergency services have been let through, while the three vans that explosives experts have been examining remain further up the road.

Emergency service personnel are gathering at a local football club, with lots of police cars and fire engines visible there.

Meanwhile, activity at RAF Fairford seems to be continuing. I heard a plane as I arrived.

The farmer who called 999 has been speaking to the BBC's Today programme.

You can listen to the full interview on the programme on Radio 4 at 07:09 BST - press listen live at the top of the page.

Police are still questioning five men who were arrested close to the base - which has been used by the US Air Force to launch attacks against Iran - this morning.

A sizeable operation was launched in the early hours of Sunday morning, raising important questions about the UK's national security after President Donald Trump claimed US and UK authorities had been working together to monitor a potential plot to attack the base.

But despite that, it appears the arrests were made after a tip-off from a member of the public - a farmer who called police after noticing "a large group of hooded and masked men" lingering near the treeline.

Image source, Reuters

"When they saw me they ran ahead of me - some into the field and some towards the neighbouring village," she said. "I then realised that something highly unusual was taking place."

She said she immediately called the Ministry of Defence but the phone rang out, and her instincts told her to call 999.

"Within 10 minutes the village was full of armed police. I think it was pure luck that I arrived in the village at a similar time to the vans," she added.

"I am absolutely staggered that it was left to me as a member of the public to see and report this. I believe that my 999 call foiled whatever plans they had."